Abstract 11780: Clinical Trial of CP Stent for Pulmonary Stenosis; The First Investigator-Initiated Clinical Trial for Pediatric Interventional Cardiology in Japan.

Introduction: Although stenting for great vessel stenosis associated with congenital heart diseases (CHD) has been established, there is no stent officially approved for pulmonary stenosis (PS). As no stent has been approved for CHD also in Japan, despite negotiation between academia and the regulatory for longer than 20 years, we decided to apply for the fund to do Investigator-Initiated Clinical Trial from Japan Agency for Medical Research and Development (AMED). Hypothesis: The efficacy of stenting for PS is better than historical data of balloon angioplasty (BA). Methods: We prospectively evaluated efficacy and safety of stenting for PS using CP stent (NuMED, Hopkinton, NY). Study was performed in 11 institutions from May 2014 to April 2017. Inclusion criteria are the following: 1) patients who have post-operative PS, 2) age <40 years, 3) weight >10 kg and 4) history of ineffective BA or findings which suggest that efficacy of BA is unlikely. The lesions as following were include: 1) systolic RV/aortic pressure >0.7, 2) systolic pressure gradient (PG) >20 mmHg in two-ventricle repair, 3) SaO2 <85% and mean PG >3 mmHg in single-ventricle repair and 4) stenosis ratio >0.5 in both single/two-ventricle repair. Primary end point is the effective ratio of stenting; effective stenting is defined as 50% increase in minimum lumen diameter (MLD) following stenting. Secondary end point are the following: 1) percent changes in MLD and re-stenosis within 12 months in both single/two-ventricle repair; 2) percent changes in systolic RV/aortic pressure and percent changes of PG in two-ventricle repair; 3) changes in SaO2 in single-ventricle repair. Results: Thirty three cases are included; the median age was 11(3-36) years and weight was 38(12-69) kg. Underling CHDs were two-ventricle in 27 cases and single-ventricle in 5 cases. Stenting was completed in 22 cases and effective in 86.4% of patients; significantly better than historical control of BA. Percent changes of MLD was 119.3±52.5%. Percent changes of systolic RV/aortic pressure was -8.5±16.1%. Percent changes of PG was -100±0%. There was no re-stenosis and serious adverse events related to CP stent. Conclusions: CP Stent implantation for PS complicated by CHD is safe and effective. [ABSTRACT FROM AUTHOR]